1. A patent titled “stereoscopic display viewable by naked eyes” (CN101594549A) includes a black baffle (2), a right convex lens (3), a left convex lens (4) and an LCD video player (7). The display is a box, a top panel of which is parallel to a bottom panel. The black baffle (2) forms three sides of the box. The right convex lens (3) and the left convex lens (4) are installed in a convex lens installing round hole of the top panel through an optical axis thereof in a parallel way respectively. The distance between the optical axis of the right convex lens (3) and the optical axis of the left convex lens (4) is 6-7 cm. The LCD video player (7) includes a screen (1), wherein the screen (1) is a display of the LCD video player (7), and the screen (1) includes a right screen (10) and a left screen (11). The right screen (10) and the left screen (11) are located in the left half part and the right half part of the screen (1) respectively. The right screen (10) and the left screen (11) are fixed on the upper surface of the bottom panel in such a way that the right screen (10) and the left screen (11) are located below the right convex lens (3) and the left convex lens (4) respectively. The distance between the screen (1) of the LCD video player (7) and the right convex lens (3) and the left convex lens (4) is 8-12 cm. The LCD video player (7) further includes a USB data transmission port (6). the USB data transmission port (6) is installed on the left side panel of the black baffle (2). See FIG. 2 and FIG. 3.
The disadvantages are as follows: first, the patent recites “the distance between the optical axis of the right convex lens (3) and the optical axis of the left convex lens (4) is 6-7 cm”, and “the distance between the screen (1) of the LCD video player (7) and the right convex lens (3) and the left convex lens (4) is 8-12 cm”, which indicates that the shortest focal distance of the optical convex lens is 8 cm. The screens as shown in the figure of the patent are arranged side by side. The maximum size of the single image arranged in parallel is unlikely to exceed 6.5 cm which is the distance between eyes of a person. The normal view angle of a film should be optically designed more than 40°. The amplification factor should be more than 3 times. The diameter of the lens is about 2 cm (this also complies with that the convex lens of the patent is a small round lens as shown in the figure). As the diameter of the lens is small, the eyes of the user should be as close as possible to the lens during watching. This mode is not substantially different from the head-mounted stereoscopic display sold in the market. It does not have the basic characteristic that the eyes can freely move up and down, left and right, forward and backward in the naked-eye stereoscopic mode. Therefore, it is hard to be called the perfect naked-eye stereoscopic characteristic. Second, the width of the image is 6.5 cm. The resolution can be 1000 pixels at most according to the resolution of the mainstream product LCD screen of the current screen, which is only half of the high-definition screen. Third, the pixel of the LCD screen is viewed under a 3-time eyepiece through which large pixel grain can be seen. this cannot meet the basic viewing requirement of the non-grainy sense of the movies.
2. The previous patent CN90217663 of the inventor of the application is titled “stereoscopic display for stereogram”. The stereoscopic display is provided with a shell (1), a planar reflector (2), a stereogram pair frame (3), a longitudinal partition board (4), a diffusion plate (5), an electric light source, a wire and a power line connecting to the electric light source. The upper end of the shell (1) is fixed to a plano-convex lens screen (6). The lens screen is composed of two identical rectangular plano-convex lenses that are combined together closely in parallel. The convex surface of the lens is oriented toward the inner cavity of the shell. The range of the focal length of the lens is 200-250 mm. The length of the lens screen is 120-140 mm. The width is 80-100 mm. The inclined inner wall of the middle of the shell (1) is fixedly provided with a rectangular planar reflector (2). The included angle between the plane of the planar reflector (2) and the lens screen (6) is 45°. The middle part of the shell which is opposite to the inner wall of the planar reflector is provided with an electric direct light source (7). The lower part of the shell is provided with the movable stereogram pair frame (3). The included angle of the plane of the frame and the planar reflector is 45°. The longitudinal partition board (4) is fixed at the middle part of the inner cavity of the shell (1) from the plano-convex lens screen to the stereogram pair frame. The diffusion plate (5) which is parallel to the framework (3) is arranged below the stereogram pair frame (3). An electric transmission light source (8) is arranged below the diffusion plate (5). a change-over switch (9) of the electric direct light source and the electric transmission light source is provided on the step on the outer surface of the lower part of the shell (1) electric light source The change-over switch (9) is connected in series in the circuit of the electric light source. See FIG. 2 and FIG. 3. The patent recites that when the traditional stereoscopic viewing device uses the eyepiece with a short focal length to view the stereoscopic image, the eyes of the user must be as close as possible to the lens. The range in which the eyes can move with respect to the lens is very small. The stereoscopic image will disappear if the eyes depart from the specific position. The disadvantages of this patent are as follows: as the lens adopts the lens whose focus range of 200-250 mm, when the lens is the plano-convex lens (not the telescope), the size of focal length is 200 mm>the image width size of 65 mm. The magnification of the image cannot be more than 1 time. Therefore, the stereoscopic image formed by this patent technology must be the small-sized image, which can be served as a certain stereoscopic image for viewing, but cannot reach the visual effect of watching the large stereoscopic image in the cinema whose field angle is more than 40°.